I installed the Fritzbox TR-064 binding (recent version 1.14), configured it and set up my items. Everything is running fine, after I restart openhab2. I get all DSL information from my FritzBox as well as I get information about anybody calling my phone number. This works for several minutes and I was happy. Now I observed, that after some time the calling indication is not working any more. I checked, that within my openhab2 log the message “Fritzbox Reconnect Job executed” appears every 2 hours. Within the forums I got the hint, that this is by purpose due to a cyclic restart of the connection. But this is not my issue, as the calling indication only works some minutes after restart of openhab.
Finally I think I found the root cause: my openhab instance is behind a Lancom router and the Lancom router is connected to the FritzBox. Within the Lancom properties there is a TCP aging interval of 300 seconds set which indicates, that every inactive TCP connection will be removed from the masquerade table after 300 secs. And this seems to be my problem with the calling monitor function of the TR064 binding.
Anybody else experienced this behaviour? Is there any chance to send a “keepalive” signal to the FritzBox port 1012 (which seems to be the relevant port for the calling monitor) by the Fritzbox binding? If not, is there any chance to get the source code of the binding to adapt the behaviour by myself?